Virtualization allows in general a creation of a virtual machine acting like a real entity. For example software executed on this virtual machine is separated from the underlying hardware resources. With regard to mobile networks comprising a core network and a radio access network, ‘RAN’, virtualization means that parts of the radio access function are executed on a centralized entity like a cloud computing platform providing “virtual” computing and network resources behaving the same or similar as hardware resources. For example one of the benefits of a virtualization is the provisioning of computing resources on-demand by means of scaling mechanisms, for example by increasing or decreasing computing resources assigned to a virtual function.
Such a conventional system with virtualization is shown in FIG. 1. A system 1 comprises physical radio access points, ‘RAPs’, 6 which are connected to a cloud computing platform 5 on which a set of virtual radio access functions VRAFs 4 is executed. Between the physical RAPs 6 and the VRAFs 4 a functional split is established. That means that parts of the function of a radio access technology protocol stack are executed in the radio access points RAPs 6 while other parts are executed as VRAFs 4. An example for radio access technologies is 3GPP (E-)UTRA like LTE and UMTS and other technologies. The cloud computing platform 5 is further connected to the mobile core network 8 and comprises a cloud management system 3. Further the cloud computing platform 5 or more precisely the cloud management system 3 is further connected to a management entity 2, i.e. in FIG. 1 a radio access network operation, administration and maintenance OAM system which monitors, administrates and configures radio access network entities 6.
Conventional radio access technology is not designed with virtualization and centralization. A combination of a radio access point and virtual radio access function VRAF builds one logical entity, i.e. a virtual base station. Interfaces towards the mobile core network 8 terminate in the cloud platform 5, more specifically in the upper part of a virtual base station protocol stack. On the lower part the RAP executes a set of lower layer RAN protocol stack functions depending on the deployment scenario. This could be for example functions of the radio access technology physical layer or functions of the radio access technology MAC layer. If a virtual base station is operative the radio access point RAP 6 is connected via an interface to a data center where the virtual functions are executed on a cloud platform, i.e. like it is shown in FIG. 1, the cloud computing platform 5. The cloud computing platform 5 allows for a dynamic instantiation of virtual functions. A set of VRAFs 4 execute the upper layer of the radio access network protocol stack as well as any other required functions being necessary for management and connectivity to other entities. As such a set of VRAFs 4 form a virtual radio access point, ‘VRAP’ 9, which is however not necessarily a logical entity on its own.